Parallel routing code patch #1 (preliminary)

Here is the first iteration of the parallel route table code. This
code was developed by Jeffrey Hsu and then further work was done on
it by me:
http://apollo.backplane.com/DFlyMisc/routing01.patch
Currently the only known bug is that ARP over token-ring will not
work properly.
This patch needs basic testing. Do 'route' commands work properly?
Are there inconsistencies between cpus? (recognized by having weird
TCP connection problems), etc etc.
This is a very preliminary patch, 'alpha' quality at best.
-Matt